1：Experimental Design and Method Selection:

The study involved screen printing PEDOT:PSS films on FTO substrates followed by post-treatment with various H2SO4 solutions (concentrated H2SO4, H2SO4 diluted with H2O or DMSO) to enhance charge transfer efficiency. Methods included adhesion tests, CS-AFM for morphology and current imaging, XPS for composition analysis, Raman spectroscopy for molecular structure, and electrochemical measurements for catalytic activity.

2：Sample Selection and Data Sources:

PEDOT:PSS films were prepared using screen-printed ink on cleaned FTO substrates. Samples were treated with different H2SO4 solutions and rinsed with ethanol.

3：List of Experimental Equipment and Materials:

Equipment included a spectrophotometer (U-2800, Hitachi) for UV-Vis transmittance, CS-AFM (NTEGRA, NT-MDT) for morphology and I-V curves, XPS microprobe (ESCALAB250, Thermo Fisher Scientific) for composition, Raman spectrometer (in Via, Renishaw) with 532 nm laser, SEM (Magellan 400, FEI) for thickness, electrochemical analyzer (Model 660C, ALS/CH Instruments) for EIS and Tafel plots, voltage current source/monitor (6246, ADCMT) and solar simulator (YSS-150A, Yamashita Denso) for J-V curves. Materials included PEDOT:PSS ink (Sigma-Aldrich), FTO glass (Nippon Sheet Glass), and various chemicals from suppliers like Sigma-Aldrich, Alfa Aesar, and Sinopharm.

4：Experimental Procedures and Operational Workflow:

FTO substrates were cleaned and treated with UV-O

5：PEDOT:

PSS ink was screen-printed using a 300 wired mesh screen. Films were immersed in H2SO4 solutions for 10 min, rinsed with ethanol, and baked at 120°C. Adhesion was tested with 3M adhesive tape. CS-AFM, XPS, Raman, SEM, and electrochemical measurements were performed as described.

6：Data Analysis Methods:

Data were analyzed using standard techniques for each instrument, including normalization of XPS spectra, calculation of electrical conductivity from sheet resistance and thickness, and interpretation of EIS and Tafel plots for catalytic activity.